These are the Lazarus sources and help files. You need to download and install all fpc and fpc sources for your platform.
For an overview what changed from previous 1.0 and 1.0x Versions
(includes incompatibilities with earlier versions) see:
- http://wiki.lazarus.freepascal.org/Lazarus_1.0_fixes_branch
- http://wiki.lazarus.freepascal.org/User_Changes_2.6.2